Nucleophiles and electrophilic centers

How to recognize nucleophiles? : The nucleophiles seek to establish, with their electronic pairs, a bond to an electrophilic center, ie. a place with a full or partial positive charge or an electron gap. So they have to be - electronic pair carriers on a neutral atom, eg $ H_3N| $ - pair carriers on a negatively charged atom, eg $ HO|^- $

How to evaluate the nucleophilic force in aqueous solution? The nucleophiles in aqueous solution are stronger if - for the same atom their - charge is great, eg $ S^{2 -} \; \gt \; HS^- $ - in a row (period) of the periodic table the atom carrying the pair is less than →       electronegative , eg $ NH_3 \; \gt \; H_2O $. (He holds back his pair less well) - in a column (family) of the periodic table: the atom carrying the pair is large (electron pairs more available, hydration which masks the pairs less important) - for the same atom the →       inductive effect to this atom is more positive, eg $ Ch_3NH_2$ (Effect $ I_+ $ gives $ e^- $, they repel the pair of the nucleophile and make it more available, the opposite is true for the $ I_-$ effect ) - for the same atom: the atom carrying the pair is less congested, eg $ NH_3 \; \ gt \; R_3N $ (pairs no longer available)

How to recognize an electrophilic center? An electrophilic center must be able to attract a peer - carrying a full positive charge, eg $ CH_3^+ $ - carrying a partial positive charge, eg $ Cl_3C^{\delta +} $ - having an electronic gap, eg $F_3B $